Gas and liquid mixer



2 A H Wk 1 D 2 x m \\\\A H Dec. 4, 1945.

Patented Dec. 4, 1945 Charles Dalrymple Macgill, Glasgow W. 3, Scotland, assignor to Barr & Stroud, Limited, Glasgow, Scotland Application August 6, 1942, Serial No. 453,895 In Great Britain July 21, 1939' This; invention refers to a method of andapparatus for adding quantities of liquid to systems in, which, gas under pressure is flowing, the invention beingmore particularly concerned with air' pressure systems, for cleaning the windows ofirangefinders and like optical instruments by directing air under pressure onto the glass, to clear away rain, spray,,soot, or the like.

In this connection, it. has been; found that where, a: deposit has. formed on the window, e. g. a. deposit of salt,,or an oily deposit. from funnel smoke on board-ship, the use of a solvent liquid with; the air may be necessary for cleaning purposes, and, the principal object of the inventionisto: provide for: the addition of charges of solvent liquid, for example, water. itself, or a solution; otfiia chemical in water, to the air.

According; to this invention, quantities. of. liquid. are. added to. asystem in. which gas under pressure is: flowing. by connecting a. container for liquid, at a position, below the; liquid level in the container; to' the pressure system, with valve control. of; the connection, so that, connecting thecontainer toathe system opensa the valve, gas underpressure passes into and up through the li'quid'zin. the container, builds up a. pressureabove ftl'lfiiliilllidi in. the container and forces liquid out window (or windows) of the rangefi-nder through arnozzle: (or'nozzles beside the' window, a connection piece in the air line: with. a branch passage-inthe connection piece; a liquid container device with a passage communicating with the==-ihterior-of the container at a position below the liquid level therein, the" container passage beingqconnected to the branch passage of the connection piece, and a valve interposed between the ail: lineandthe. container, the said passages when thevalve. is pen. servingboth for inlet of air to the container (where it. rises; up. throughthe liq.- uids andtcreatesz apressure above it) audio: out.- let; atgliquidzfrom. thecontainer pashthe entering intoithe? airline; to! bercarried. awayand discharged as a spray on to the window with the air.

The container device is readily attachable to and removable from the connection piece, and the branch passage of the connection: piece has a valve in it which serves to close the branch passage when the container device is not applied, and the passage of the container device also-has a valve in it which normally closes the passage from the container.

When the container device is removedfrom the connection piece, the branch passage of the connection piece is closed by a valve which isopened by the action of applying the container device and closes of itselfwhen the container device isre moved.

The invention, as appliedto a range'finder window cleaning system will now be described with reference to the accompanying drawing, in which:

Figure 1 shows, mor or less diagrammatically, arangefinder equipped with a compressed. air window cleaning system, and

Figure 2' is aside sectional view showing the container device for introducing liquid into the air system.

Figure 3 is a detail, fragmentary, view,- partly in vertical'section and partly in elevation showing the valve in the branch passage in an open position, resulting from application ofthe container device to the connection piece.

Figure 1- shows rangefinder A, air'pumpB, and liquid container device 0'.

The pumpB delivers air under pressure by way r of amaindelivery'tube' I, a connection piece: D,

and tubes 2 to each of the" windows 3: of the rangefind'er, on to which the air is' directed from a nozzle 4" at the end of each of the tubes 2.

.The connection piece D is shown; in detailin Figures 2 and 3' and comprises a central limb 5,ua cross-part 5a constituting two branchconnections 6' for the tubes 2, an airinlet connection 1, and a branch passage 8 controlled by an outwardlyclosing'ball valve 9 having a seat 9a and spring IU. An enlargedportion in the upper end of the branch passage 8' forms achamber Na and an inner tube lfexten'ds' from the said chainber lla into the cross-part 5a of the connection piece D. 4

When the window cleaning system is function'- ing without the container device being 'fit'tedin place, the branch passage 8 is closed by the ball valve 9 and air from thepump B passes into the connection piece D and is distributed" to the tubes by way of the connections 6, and thence to the windows 3.

The container device C comprises a cylindrical container 12 with a neck [3 through which an air inlet and liquid outlet port l9 extends, and a valve [4 controlling the port I9. At the side of the container l2 there is a sight tube I5 and at the opposite end from the neck l3 there is a filling opening 16 with a screw closure cap. The valve I4 is a cylindrical slide valve with a groove I ia around the valve body, and having an operating head I 412, and a spring l8 acting on the valve body to keep the valve closed.

For use, the container device C'is applied to the connection piece D as shown in Figure 2 and secured by a union nut I? so that the branch passage 8 of the connection piece communicates with the port I9, the neck l3 depressing the ball valve port l9 and groove Ma past the valve 9 through tube ll into the air line and is ejected with the air in the form of a fine spray against the windows 3.

On releasing the valve head, the valve l4 closes and cuts oi the liquid supply so that dry air is delivered to the windows, after the liquid already in the system has been ejected.

The container l2 must in use be closed to atmospheric pressure.

To avoid undue consumption of the solvent liquid, the following procedure may be adopted. The operator starts the motor of the pump B and presses the head of the valve I4 for two or three seconds so as to build up a pressure in the interior of the container I2. He then releases the valve and stops the pump motor. Next he presses the valve head again, noting a limited fall in the liquid level as shown by the sight tube 15. Thereafter he releases the valve head and re-starts the motor, as a result of which the charge of liquid which has entered the air system is discharged on to the windows through the nozzles 4. This charge will usually be sufiicient to remove a deposit from the windows.

After the introduction of a charge of liquid into the air system the container l2 may be removed from the connection piece D in which case the valve 9 automatically closes. If more than one rangefinder is fitted with a Window cleaning system of this kind, the container may be transferred from one system to another, as required.

I claim:

1. In apparatus for' selectively delivering air or air and liquid under pressure, the combination of a source of supply of air under pressure, a connection piece of substantially T-form having a passage in its central limb communicating with a passage in its cross-part, and a valve chamber in the passage of said central limb remote from the point of connection of said passages, piping for conveying the air under pressure to the passage of said central limb, piping connected to each outlet of the cross-part of said connection piece, provided with a nozzle, an inner tub in end communicating only with said valve chamber and its other end communicating with the passage of said cross-part, and disposed so as to leave an annular space around the inner tube separated from the valve chamber, whereby said air under pressure is required to pass through said annular space in a direction away from said valve chamber and then into and through said inner tube to the valve chamber, anoutwardly closing valve in said valve chamber, a liquid container removably fitted to said connection piece at the end of said central limb adjacent said valve and adapted to unseat said valve when the liquid container is connected to said connection piece, said liquid container provided with a port communicating with said valve chamber beyond said valve and with the container interior at a position below the liquid level therein, and a valve in said port for controlling inlet of air to and exit of liquid from said container.

2. In apparatus for selectively delivering air or air and liquid under pressure, the combination of a source of air under pressure, a spray nozzle, and piping forming an air line for conveying air under pressure to said spray nozzle, said air line including a connection piece provided with a branch passage, a liquid container removably fitted to the connection piece with a passage in the container communicating with its interior at a position below the liquid level in the container and connected to the said branch passage, a valve in the branch passage to close that passage when the container is not applied, and a valve in the passage of the container to close the container when removed from the connection piece, the said connected passages when the valves are open serving both for inlet of air to the container and for outlet of liquid from the container past the entering air and into the air line to be carried away and discharged as a spray in quantities depending on the amount and duration of opening of the valves.

3. In apparatus for selectively delivering air or air and liquid under pressure, the combination of a source of air under pressure, a spraynozale, and piping forming an air line for conveying air under pressureto said spray nozzle, said air line including a connection piece provided with a branch passage, a liquid container removably fitted to the connection piece with a passage in the container communicating with its interior at a position below the liquid level in the container and connected to the said branch pas- I sage, a valve in the branch passage which is opened by the action of applying th container to the connection piece and which closes of itself when the container is removed, and a valve in the passage of the container to close the container when removed from the connection piece, the said connected passages whenthe valve of the container is open serving both for inlet of air to the container and for outlet of liquid from the container past the entering air. and into the air line to be carried away and discharged as a spray in quantities depending on the amount and duration of opening of the valve in the passage of the container.

4. In apparatus for selectively delivering air or air and liquid under pressure, the combination of a source of air under pressure, a spray nozzle, and piping forming an air line for conveying air under pressure to said spray nozzle,

said air line including a connection piece provided with a branch passage, a liquid container interior at a position below the liquid level in the container and connected to the said branch passage, a valve in the branch passage which is opened by the action of applying the container to the connection piece and closes of itself when the container is removed; and a valve in the passage of the container which is opened by hand and self-closing when released to close the container when removed from the connection piece,

the said connected passages when the valve of the container is open serving both for inlet of air to the container and for outlet of liquid from the container past the entering air and into the air line to be carried away and discharged as a spray in quantities depending on the amount and duration of opening of the valve in the passage of the container.

CHAS D MACGILL. 

